Since thienamycin having a broad antibacterial spectrum was disclosed in U.S. Pat. No. 3,950,357, there have been many attempts to develop an even more active antibiotic which is stable against the attack of dehydropeptidase-I.
For instance, European Patent No. 126587 reports meropenem and Japanese Patent No. 425779 presents biapenem, for use in injection formulations. Recently, European Patent No. 416953 have disclosed tribactam compounds, which are carbapenem antibiotics suitable for oral administration.
However, the above carbapenem antibiotics have a problem in that the process of isolating the intended isomer is complicated, requiring more than 12 steps. Further, they show low antibacterial activities against Streptococcus facium and Enterobacter cloacae, and no activity against Pseudomonas aeruginosa.
Therefore, there has been a need to develop an antibiotic having an improved antibacterial activity against Gram-positive and Gram-negative bacteria.